WELL JET DEVICE

DISPOSITIF DE PUITS A JET

English Abstract

The invention relates to pumping equipment. The inventive jet device comprises
a packer, a pipe
column and a cradle in which drain ports are embodied and on which a jet pump
is mounted in a
body. Said body is provided with a channel for supplying an active medium to
the nozzle, a
channel for supplying a pumped-out medium, and a channel for evacuating the
mixture of said
mediums. The body also comprises a through channel embodied therein above the
channel for
supplying a pumped-out medium, connected thereto and used for arranging a
sealing unit. Said
sealing unit comprises a channel capable of containing a cable for the purpose
of installing
instruments and equipment in the well below the jet pump. The channel for
supplying a
pumped-out active medium is connected to the drain ports and to the space
around the pipe
column by means of said ports. The channel for evacuating the mixture of the
mediums from the
jet pump is connected to the internal space of tubes above the jet pump. The
sealing unit is
embodied in such a way that it makes it possible to arrange thereinside a
mechanism for bringing
in the well and extracting therefrom the body containing the jet pump. A
threaded hole for
connecting autonomous measuring instruments to the body is embodied in the
lower part thereof.

French Abstract

L'invention concerne les équipements de pompage. Le dispositif de puits à jet comprend un packer, une colonne de tubes dotée d'un support comportant des orifices de drainage et une pompe à jet installée dans un corps sur ledit support. Le corps comprend un canal d'amenée du milieu actif à une tuyère, un canal d'amenée de milieu pompé et un canal d'évacuation du mélange des milieux. Dans le corps au-dessus du canal d'amenée de milieu pompé est réalisé un canal de passage relié au canal d'amenée et servant à monter une unité d'étanchéité. Dans cette unité d'étanchéité on réalise un canal axial qui sert à faire passer le milieu pompé d'un câble et un canal d'amenée du milieu pompé du câble, qui est utilisé pour monter des instruments et des équipements. Le canal d'amenée du milieu actif est relié aux orifices de drainage et à travers ces orifices vers l'espace autour de la colonne de tubes. Le canal d'évacuation du mélange des milieux de la pompe à jet est relié à l'espace interne des tubes au-dessus de la pompe à jet. L'unité d'étanchéité est réalisée de façon qu'il soit possible de monter à l'intérieur de cette unité un mécanisme d'apport et d'extraction du corps avec la pompe à jet. Un orifice fileté formé dans la partie inférieure du corps sert à monter sur ce corps l'équipement de mesure.

Claims

What is claimed is:
1. A well jet unit which comprises a packer, a piping string having a support
wherein drain
ports are made and onto which a jet pump in a housing is installed, the said
housing of the said
pump comprising: a passage for supplying an active medium to a nozzle of the
jet pump, a
passage for supplying a medium pumped out of a well to the jet pump, and a
passage for
removing a media mixture from the jet pump, and in the housing, above the
passage for
supplying the pumped out medium, a through passage in communication with the
passage for
supplying the pumped out medium and being made with a mounting face for
installing a sealing
assembly, and the sealing assembly comprises an axial passage and both the
axial passage and
the said passage for supplying the pumped out medium have a cable led
therethrough for the
purpose of installing, in the well below the jet pump, instruments and
equipment in a manner
such that the instruments and equipment are moveable along a well bore when
the jet pump is
or is not operated, characterized in that, according to this invention, the
passage for supplying
the active medium to the nozzle of the jet pump communicates with the drain
ports and, through
the drain ports, with the space surrounding the piping string, the passage for
removing the media
mixture from the jet pump communicates with an inner cavity of the piping
string above the jet
pump, the through passage is made in a manner such that the through passage
with a closure of
the through passage comprises a device for delivering into and removing from
the well the
housing with the jet pump, and in the bottom part of the housing of the jet
pump a threaded hole
is made for attaching autonomous measuring equipment to the housing, wherein
the outer
diameter (D) of the jet pump housing is at least 1.0 mm less than the least
inner diameter (D1)
of the piping string, the diameter (D2) of the axial passage in the sealing
assembly is at least 0.01
mm greater than the diameter (D3) of the cable, and the diameter (D4) of the
passage for
supplying the pumped out medium is at least 2 mm greater than the diameter
(D3) of the cable,
and sealing rings and a retaining mechanism being installed on the housing of
the jet pump.
7

Description

CA 02438877 2003-08-19
WELL JET DEVICE
Field of Invention
This invention relates to the field of pumping engineering, mainly to downhole
jet units for oil
production.
Prior Art '
Known in the art is a downhole jet unit comprising a jet pump installed on the
production string
in the well and a geophysical instrument placed in the production string below
the said jet pump
(RU 2059891 C 1 ).
The said jet pumping unit enables to pump different extracted media, e.g.,
oil, out of the well
with the simultaneous treatment of the extracted medium and the well formation
zone, but the
said unit provides for supply of a working medium to the nozzle of the jet
unit along the string,
which in some cases narrows the field of application of the said unit.
The closest, as to its technical essence and the achievable result, to this
invention is a downhole
jet unit comprising a packer, a piping string having a support wherein drain
ports are made and
onto which a jet pump with its housing is installed, the said housing of the
said pump comprising
a passage for supplying an active medium to the nozzle of the jet pump, a
passage for supplying
the medium, as pumped out of the well, to the jet pump and a passage for
removing a medium
mixture from the jet pump, and in the housing, above the passage for supplying
a pumped out
medium, a through passage in communication with the latter being made with a
mounting face
for installing a sealing assembly, and the sealing assembly comprises a
through passage with the
possibility of leading, through the latter and the said passage for supplying
the pumped out
medium, a cable for the purpose of installing, in the well below the jet pump,
instruments and
equipment with the possibility of moving them along the well bore when the jet
pump is or is not
operated (RU 2143597 C1).

CA 02438877 2003-08-19
The said downhole jet unit enables to perform various production operations in
the well below
the jet pump installation level by, inter alia, reducing a pressure difference
both above and below
the sealing assembly. However, the said downhole jet unit does not enable to
utilize its
possibilities in full due to non-optimal relationships between dimensions of
various components
of the construction of the downhole jet unit and due to such arrangement of
the jet pump in its
housing that is non-optimal for a number of applications.
Disclosure of Invention
The objective of this invention is to optimize the arrangement and the
dimensions of various
components of the construction of the well jet unit and, owing to it, to raise
the reliability of
operation of the well jet unit.
The stated objective is achieved owing to the fact that the well jet unit
comprises a packer, a
piping string having a support wherein drain ports are made and onto which a
jet pump with its
housing is installed, the said housing of the said pump comprising a passage
for supplying an
active medium to the nozzle of the jet pump, a passage fox supplying the
medium, as pumped out
of the well, to the jet pump and a passage for removing a media mixture from
the jet pump, and
in the housing, above the passage for supplying a pumped out medium, a through
passage in
communication with the latter being made with a mounting face for installing a
sealing
assembly, and the sealing assembly comprises a through passage with the
possibility of leading,
through the latter and the said passage for supplying the pumped out medium, a
cable for the
purpose of installing, in the well below the jet pump, instruments and
equipment with the
possibility of moving them along the well bore when the jet pump is or is not
operated, wherein,
according to this invention, the passage for supplying the active medium to
the nozzle of the jet
pump communicates with the drain ports and through the latter with the space
surrounding the
piping string, the passage for removing a media mixture from the jet pump
communicates with
the inner cavity of the piping string above the jet pump, the through passage
is made with the
possibility of installing in it, with the closure of the through passage, a
device for delivering into
and removing from the well the housing with the jet pump, and in the bottom
part of the housing
2

CA 02438877 2005-10-14
of the jet pump a threaded hole is made for attaching autonomous measuring
equipment to the
housing, wherein the outer diameter (D) of the jet pump housing is at least
1.0 mm less that the
least inner diameter (Dl) of the piping string, the diameter (D2) of the axial
passage in the sealing
assembly is at least 0.01 mm higher than the diameter (D3) of the cable, and
the diameter (D4) of
the passage for supplying the pumped out medium is at least 2 mm higher than
the diameter D3
of the cable, and sealing rings and a retaining mechanism are installed on the
housing of the jet
pump.
The analysis of the operation of the well jet unit has shown that its
reliability may be increased
through more optimal arrangement of the construction components in the jet
unit housing and
making them according to strictly defined dimensions. It has been found out,
in particular, that
the diameter of the passage for supplying the pumped out medium may not be
taken arbitrarily. It
is due to the fact that a too large diameter of the passages results in a
reduction in the strength of
the unit, but a too small diameter of those passages results in lowering the
capacity of the jet
pump. It has been found out in this connection that the making of the diameter
of the passage for
supplying the pumped out medium at least 2 mm greater than the diameter of the
cable enables to
pass to the jet pump the greatest amount of the medium pumped out of the well,
which
corresponds to the maximum capacity of the jet pump, with the minimal
hydraulic losses. As to
the upper limit, it should be defined by the strength characteristics of the
jet pump construction,
and, first of all, by those of the jet pump housing. In each particular case
this value is to be
determined individually. In the course of the unit operation studies of
different well modes are
conducted. It is necessary to install and remove the housing with the jet pump
in the piping
string. It has been determined that it is advisable to make the diameter of
the jet pump housing at
least 1.0 mm less than the inner diameter of the piping string, and sealing
rings and a mechanism
which retains the jet pump housing in its position relative to the support in
the well. In the result,
possible sticking of the housing in the piping string is precluded and the
overflowing of the
medium from the space above the housing to the under-packer space in the well
is ensured. It has
already been said that in the process of the unit operation it is necessary to
move instruments and
equipment installed on the cable along the well and, at the same time,
minimize the medium flow
through the axial passage of the sealing assembly. It has been achieved by
making the diameter
3

CA 02438877 2005-10-14
of the axial passage in the sealing assembly at least 0.01 mm greater than the
diameter of the
cable, onto which the instruments and equipment are installed. The making of a
threaded hole in
the bottom part of the jet pump enables to install various measuring devices
operating
autonomously, and, owing to this, expand the range of studies conducted in the
well.
Thus, the objective of the invention - to optimize the arrangement and the
dimensions of the
construction components of the unit and, owing to it, raise the reliability of
operation of the
downhole jet unit - has been achieved.
Brief Description of Drawings
FIGURE 1 represents a longitudinal section of the disclosed well jet unit.
FIGURE 2 represents a longitudinal section of the well jet unit with the
device for delivering into
and removing from the well the housing with the jet pump, which is installed
instead of the
sealing assembly.
Preferred Embodiment of the Invention
The proposed well jet unit comprises a packer 1, a piping string 2, having a
support 3 wherein
drain ports 4 are made and onto which a jet pump 6 with its housing 5 is
installed, the said
housing 5 comprises: a passage 7 in communication with drain ports 4 for
supplying an active
medium to the nozzle 8 of the jet pump 6 from the space surrounding the piping
string 2, a
passage 9 for supplying the medium pumped out of the well to the jet pump 6
and a passage 10
for removing a medium mixture from the jet pump 6 into the inner cavity of the
piping string 2
above the jet pump 6, and in the housing 5 above the passage 9 for supplying
the pumped out
medium a through passage 11, being in communication with the passage 9 and
being made with
a mounting face 12 for installing a sealing assembly 13, and the sealing
assembly 13 comprises
an axial passage 14 with the possibility of leading, through it and the
passage 9 for supplying the
pumped out medium, a cable 15 for the purpose of installing on it, in the well
below the jet pump
4

CA 02438877 2003-08-19
6, instruments and equipment with the possibility of moving them along the
well bore when the
jet pump 6 is or is not operated. The through passage 11 is made with the
possibility of installing
in it, with the closure of the through passage 11, a device 17 for delivering
into and removing
from the well the housing 5 with the jet pump 6, and in the bottom part of the
housing 5 of the jet
pump 6 a threaded hole 18 is made for the purpose of connecting with the
housing 5 of the
autonomous measuring equipment 21, wherein the outer diameter (D) of the
housing 5 of the jet
pump 6 being at least 1.0 mm less than the least inner diameter (D,) of the
piping string 2, the
diameter (D2) of the axial passage 14 in the sealing assembly 13 is at least
0.01 mm greater than
the diameter (D3) of the cable 15, and the diameter (D4) of the passage 9 for
supplying the
pumped out medium being at least 2 mm greater than the diameter (D~) of the
cable 15, the
sealing rings 19 and the retaining mechanism 20 being installed onto the
housing 5 of the jet
pump 6.
The piping string 2 with the packer 1 and the support 3 are lowered into the
well, and the packer
being installed above the producing formation. Then the packer 1 is put into
the operating
position where it divides the well space surrounding the piping string 2. Then
the housing 5 with
the jet pump 6 and the sealing assembly 13 as welt as the instruments and
equipment arranged on
the cable 15 below the housing 6 are lowered into the well. The housing 5 with
the jet pump 6
are fixed in the support 3 by using the retaining mechanism 20. The working
medium, e.g.,
water, salt solution, oil, etc., is pumped into the hole clearance surrounding
the piping string 2.
From the hole clearance the working medium flows through the ports 4 and the
passage 7 into
the active nozzle 8 of the jet pump 6. Within several seconds after the.
pumping of the working
medium through the active nozzle 8 a stable jet is formed at its outlet,
which, flowing out of the
nozzle 8, entrains the medium surrounding it into the jet pump 6, which
results in a pressure
reduction, first, in the passage 9 for supplying the pumped out medium and
then in the under-
packer space in the well, thus creating a pressure drawdown onto the producing
formation. The
pressure reduction value depends on the speed at which the working medium
comes through the
active nozzle 8, such speed depending, in its turn, on the pressure at which
the pumped out
medium is discharged into the hole clearance above the packer 1. In the result
the formation
medium comes along the piping string 2 and through the passage 9 into the jet
pump 6 where it is

CA 02438877 2003-08-19
mixed with the working medium, and the mixture of the media flows by the
energy of the
working medium along the piping string 2 from the well on the surface. During
pumping out the
formation medium with the use of the equipment and instruments 16 installed on
the cable 15 the
parameters of the pumped out formation medium are monitored, and the producing
formation is
influenced by physical fields. According to a set task it is possible to move
the instruments and
equipment 16 along the well. If the installation of the instruments and
equipment 16 on the cable
15 below the housing 5 of the jet pump 6 is not necessary, the device 17 is
installed in the
through passage 11 instead of the sealing assembly 13, and the device 17 is
used for installing
into and removing from the piping string 2 the housing 5 with the jet pump 6
and the
autonomous measuring equipment 21, if the latter has been installed on the
housing 5.
Industrial Applicability
This invention may be applied in testing, developing and operating oil and gas
condensate wells
as well as during workover jobs on them.
6

Representative Drawing